PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • If the email recipient domain does not belong to the mail server itself, the server will (quite rightly) be suspicious of the message and require some sort of proof to verify that the sender is a trusted source and not a spammer or malicious user trying to abuse the system.
http://www.w3.org/ns/prov#wasQuotedFrom
  • serverfault.com